In one sentence: It’s National Lampoon’s Vacation, without the hilarity.
In many sentences: This movie does have many funny moments, but I wonder if they are funny because they are just straight up funny, or if they are funny only compared to the depression that set up the gag. You feel sorry for this dysfunctional family: a failing inspirational speaker dad, a family-hating son, a drug-addict granddad, a suicidal uncle, a happy and sad daughter, and a mother just trying to keep it all together. Ninety percent of the family interaction is depressing, and then you get the ten percent funny.
The ending is comical because of how embarrassing it is. You laugh because most everything leading up to it has brought you so low that it’s a relief to see the family happy in their embarrassment.
It’s not a bad movie; it’s just not my kind of entertainment. The acting is great, and the writing is good. But the story is not happy. I like a happy comedy, not a depressing comedy.